The Mediterranean diet was named the fourth best overall diet and the best plant-based diet by U.S. News & World Report, though it's less of a structured weight loss strategy and more a set of eating guidelines. The Mediterranean diet emphasizes fresh produce, whole grains, monounsaturated oils, nuts and lean protein sources like seafood and poultry, though it's simple for a vegetarian to substitute plant-based proteins for animal proteins on the plan. If you're a strict vegetarian who does not consume any form of animal-based product, talk to your doctor about ways to make certain your diet includes enough of certain nutrients like vitamin B-12.

Produce and Whole Grains

According to a Mediterranean diet food pyramid developed by the World Health Organization, the Harvard School of Public Health and Oldways, a nonprofit organization that focuses on nutrition education, the bulk of a person's meals on the Mediterranean diet should be based on whole grains and a wide variety of fresh fruits and vegetables. Vegetarians following the Mediterranean diet should aim to have at least six daily servings of minimally processed fruits and vegetables, says MayoClinic.com. Whole-grain cereals, breads and pastas should be eaten at every meal.

Beans, Legumes, Nuts and Seeds

Dried beans and legumes, nuts and seeds play a crucial role in the diet of a vegetarian adhering to the Mediterranean plan. Like grains and produce, the Mediterranean diet food pyramid recommends that at least one of these items should be present in every meal. These plant-based foods are rich in protein, but, unlike soy products and quinoa which are complete sources of protein, they don't contain all of the amino acids that your body requires. However, by eating different types of high-protein plant foods throughout the day, the Centers for Disease Control and Prevention assures that you'll easily obtain adequate protein.

Dairy Products and Eggs

If you're a lacto-ovo vegetarian -- a vegetarian who doesn't eat meat, poultry or seafood, but who does consume eggs and dairy products -- you can have low- or nonfat dairy items like cheese, yogurt or milk daily and as many as seven eggs per week on the Mediterranean diet, according to the Oldways Mediterranean diet pyramid. The Dietitians of Canada says that people who don't have diabetes, heart problems or high blood cholesterol can safely consume one whole egg a day without increasing their risk of heart disease, though the group cautions that you should have two eggs or fewer weekly if you already suffer from heart disease. When counting your egg consumption, be sure to include any eggs used during cooking or in baked goods.

Fats

Olive oil is a primary source of fat in the Mediterranean diet. Use it instead of butter when cooking or as a spread or dip for whole-grain bread. You can also drizzle olive oil over vegetables or pasta. Another fat encouraged is canola oil.

Beverages

All followers of the Mediterranean diet, including vegetarians, should drink plenty of water each day. The Mediterranean diet also includes drinking wine in moderation, especially red wine. The wine should be consumed with meals, and should not exceed 5 ounces per day for women and 10 ounces a day for men. MayoClinic.com notes that if you have a history of alcohol abuse or suffer from liver or heart disease, you should avoid consuming any type of alcohol.